Performance lost on aftermarket exhaust?

[rp17]

Question to everyone running a after market exhaust. Have you noticed any performance loss after installing a after market exhaust? Each exhaust claims to add ponies but does it take from the midrange while adding to the top? Just added a exhaust and I'm not sure what my butt dyno is telling me?

[trimer]

Originally Posted by rp17

Question to everyone running a after market exhaust. Have you noticed any performance loss after installing a after market exhaust? Each exhaust claims to add ponies but does it take from the midrange while adding to the top? Just added a exhaust and I'm not sure what my butt dyno is telling me?

I did a fabspeed on one of my cars and a GHL on the other car. I would say no major butt dyno HP increase but increase in throttle response and noise was so much better. Both felt quicker off the line but as far as increase...just went off what Fabspees says.

[rp17]

..............Double post ignore.

[rp17]

I don't know Trimmer. Sound is definately a plus. But eventhough it sounds faster, it seems like it doesn't quite pickup speed til later on at some point. Did some searches and seems like removing seconday cats helped for 986 owners. I'm in a 987 so that won't help me. Does adding a exhaust change the dyno curve?

After fitting the exhaust, me and brother travelling to a gas station. At a stop light, brother in G35 decides to take off unannounced to me, when it turned green. I had no clue, so I gave chase. (I know I know not good practice) He had a jump on me but his car kept pulling and pulling until I got to maybe 3rd gear. At that point it started gaining quickly before I shut it down. Don't know if we raced before but I've never had any other car pull on me like that pre exhaust. My car is way lighter than his too. Is this the top end gain and mid range lost? Not sure if I'm liking that.

Is this the reason why others add a tune?

[trimer]

What exhaust did you put on?

[rp17]

Originally Posted by trimer

What exhaust did you put on?

Fabspeed Race Exhaust.

[trimer]

Originally Posted by rp17

Fabspeed Race Exhaust.

I would suspect you aren't losing anything. That is a nice exhaust. But fabspeed site should have all that data for sure. I was going to do the race exhaust and talked to them several times about it.

[Jake Raby]

You act surprised.. Most every system that we've actually worked with through development loses something over the stock arrangement on most engines.

That includes the well advertised, shiny, expensive stuff. My wife set 5 land speed records with a stock muffler on a 996.

[BruceH]

I did the secondary cat deletes when I put my exhaust on and definitely felt the difference, but like you mentioned mine is a 986.

[rp17]

Jake can you elaborate on that? I've read post by you and others but can't find any on my searches righ now.

[Porsche9]

Originally Posted by rp17

Jake can you elaborate on that? I've read post by you and others but can't find any on my searches righ now.

I too am interested in learning more. I'm interested in dropping the secondary cats and leaving the stock muffler. Is that even worth while? Looking for some extra throttle response and extra hp would be nice but not expecting it.

[Jake Raby]

Originally Posted by rp17

Jake can you elaborate on that? I've read post by you and others but can't find any on my searches righ now.

Not really. Search my posts from 2008- 2009 for some details… Back in those days I could tell the truth and go into detail with it a little more than I can today- people are so damn soft and sensitive these days.
One system lost 17HP after being fitted at a cost of 3K bucks.

About the only gain I see is that most systems are lighter weight than stock.

The brighter it shines the more people like it. Thats never made any sees to me for an exhaust system. Here all we care about is efficiency and effectiveness.

[Nine8Six]

Originally Posted by rp17

Is this the reason why others add a tune?

RP - a visit to your local "Porsche performance" tuner is required. Not a job for the average indy who specialize in changing genuine parts (type dude). I believe you guys have a few Porsche "performance" shops scattered across the usa so I am not too worried for your somehow lost hp... I'm worried about your wallet tho :/

Although those dynamic maps/curves are, dynamic, they most likely need tweaking for 'some' of the conditions you'd like your car to run best for. Those incl aftermarket performance exhaust systems

[jb92563]

Originally Posted by Porsche9

I too am interested in learning more. I'm interested in dropping the secondary cats and leaving the stock muffler. Is that even worth while? Looking for some extra throttle response and extra hp would be nice but not expecting it.

I did the TS mufflers alone, first and then to get rid of the drone I did the 2nd cat deletes.

There was an immediate significant improvement in throttle responsiveness and the drone went away when the 2nd cats were removed.

There was no noticeable power increase although the quicker take off from a standing start made it seem like it.

I would say that if you only did the 2nd cat delete you would also get the faster throttle response and it would likely change the tone of your stock muffler a bit.

In any case it would be a cheap way to improve the drive-ability.

[rp17]

Originally Posted by trimer

I would suspect you aren't losing anything. That is a nice exhaust. But fabspeed site should have all that data for sure. I was going to do the race exhaust and talked to them several times about it.

Trimmer it is a nice exhaust. And in there defense, I didn't buy there whole package. And also didn't buy it new so don't know how much questions they would tolerate from me.

[rp17]

Originally Posted by Nine8Six

RP - a visit to your local "Porsche performance" tuner is required. :/

Although those dynamic maps/curves are, dynamic, they most likely need tweaking for 'some' of the conditions you'd like your car to run best for. Those incl aftermarket performance exhaust systems

986, I think your right. I don't even think I ever mentioned to anyone about the Hp gains. Didn't do it for that. Now I need a trottle body and a tune? Tried my best not to go down this route but it looks like its something I will continue to fight off right now.


Jake, it is shinny with a hint of bronze, but not expensive for me. Like I said to Trimmer, I bought used from a forum member. I can clearly understand from your stand point when adding a after market exhaust to your engine and getting things that are not ordinary with what comes with the stock setup. Glad to know that Porshe put some time into making this exhaust unlike the...... well you know.

Still have my stock exhaust sitting in the garage. Don't think I can go back to it though but will hold onto it. Sorry to sound like a complainer because I do like it. Innitially didn't name my exhaust because I didn't want to come across bashing them. The race exhaust sound is incredible. I can actually hear my exhaust now just cruising around with the top down. Never saw the big idea of videos going under bridges but when I do, it freaks people out including me the first time.

So the message to other who want a louder sound, you may not even notice what I've noticed. I'm suprised actually how good I know my car now. (butt dyno was on it) But like Jake said they may not be as good as the factory performance wise. I need to do some more reading. Thanks everyone.

[rp17]

Not my video but this is similar to what it sounds like.

https://www.youtube.com/watch?v=r01lqAJZyb8

[thstone]

Check out this post: http://986forum.com/forums/general-discussions/51783-top-speed-pro-1-catback-exhaust-hp-increase.html

[rp17]

Originally Posted by thstone

Check out this post: http://986forum.com/forums/general-discussions/51783-top-speed-pro-1-catback-exhaust-hp-increase.html

That is a good exhaust. Heard these exhaust first hand and it gets my stamp of approval. Plenty of forum members running this exhaust. I went off the deep end and wanted loud.

These pipes are the 2inch ones compared to the 3inch ones on my car. (not actual specs) Still reading to figure out the significance.

[Jake Raby]

The general consensus is a performance exhaust has less restriction than stock and therefore leans the engine out.. We see the exact opposite of this and we have to tune the over- enrichment from the engine at most all RPM points, especially above 4,750 RPM. Lots of the drones people complain about are aggravated by rich running.